Personal hygiene habits typically include a means for reducing human body odor. These habits include routine bathing or washing of the body, particularly the axilla, and treating the axilla with compositions to retard odor formation, such as antiperspirant or deodorant compositions.
Antiperspirants generally include an astringent material in a suitable carrier. Astringent materials typically used in antiperspirants are metal salts, particularly aluminum and zirconium metal complexes. Exemplary metal salts are disclosed in Plechner, Antiperspirants and Deodorants, 2 Cosmetics, Science and Technology, Balsam and Sagafin, 374-400, 1972; incorporated herein by reference.
Antiperspirant compositions can be formulated in a variety of ways, each dependent on the particular ingredients involved. Such formulations include lotions, solid sticks, and creams. Solid stick formulations include gel sticks, which contain a liquid material and gelling agents.
One significant disadvantage of typical antiperspirant gel stick compositions is a tendency of the gelling agent to interact with acidic components present in antiperspirant actives or cationic species from other ingredient raw materials. This interaction between the gelling agent and the antiperspirant active can result in discoloration, odor, reduced efficacy of the actives, poor gel formation, and lower gel stability over time of any gel which is formed. The interaction may also cause processing difficulties at the temperatures and holding times typically encountered during manufacture. Antiperspirant gel stick compositions may have additional disadvantages such as a wet, cold and sticky feel on the skin, skin irritation, and shrinkage and containment problems due to high volatility.
It is an object of the subject invention to provide low-aqueous antiperspirant gel compositions with greater gel stability during manufacture, increased efficacy of the active as compared to current antiperspirant gel formulations, and reduced discoloration and odor.
It is also an object of the subject invention to provide low-aqueous antiperspirant gel stick compositions with greater gel stability during manufacture, increased efficacy of the active as compared to current antiperspirant gel formulations, and reduced discoloration and odor.
It is a further object of the subject invention to provide a process for the manufacture of low-aqueous antiperspirant gel compositions wherein the interaction between the active and gelling agent is reduced such that superior gel formation and greater gel stability can be achieved during manufacture, as well as reduced discoloration and odor.